s1_generate_a_series_of_files() {
    for i in {1..100}; do
        echo "$i" > "/tmp/new_file$i"
    done
}


s2_list_4_files_in_long_format_about_account_and_group() {
    ls -l /etc/passwd /etc/group /etc/shadow /etc/gshadow | sort
}


s3_find_items_related_to_given_username() {
    sort <(grep "$1" /etc/passwd) <(grep "$1" /etc/shadow)
}


s4_find_items_related_to_given_group_name() {
    sort <(grep "$1" /etc/group) <(grep "$1" /etc/gshadow)
}


s5_create_groups_for_given_group_names() {
    groupadd "rnd"
    groupadd "itoperation"
}


s6_create_users_and_set_their_group_as_required() {
    useradd "adam" -g "rnd"
    useradd "bob" -g "rnd"
    useradd "calvin" -g "itoperation"
    useradd "david" -g "itoperation"
    useradd "edward" -g "rnd"
}


s7_change_users_shell() {
    usermod -s /usr/bin/sh "adam"
    usermod -s /usr/bin/sh "edward"
}

s8_set_password_change_policy() {
    chage -m 10 -M 60 -W 50 "adam"
    chage -m 10 -M 60 -W 50 "bob"
    chage -m 10 -M 60 -W 50 "calvin"
    chage -m 10 -M 60 -W 50 "david"
    chage -m 10 -M 60 -W 50 "edward"
}


s9_set_password_for_five_users() {
    chpasswd <<< "adam:$1"
    chpasswd <<< "bob:$2"
    chpasswd <<< "calvin:$3"
    chpasswd <<< "david:$4"
    chpasswd <<< "edward:$5"
}


s10_lock_bobs_password() {
    passwd -l "bob"
}


s11_include_adam_into_wheel_group() {
    usermod -G wheel "adam"
}


s12_change_files_permission() {
    for i in {3..99..3}; do
        chmod 640 "/tmp/new_file$i"
    done
}
